One vertex per element, one color per generator, with an edge from x to x·s.
(9,10,15,12)(11,16,13,17)(14,20,22,18)(19,24,21,23)(25,26,29,30)(27,33,35,31)(28,32,36,37)(34,39,40,38)(2,5)(7,8)(9,11)(10,16)(12,17)(13,15)(14,21)(18,24)(19,22)(20,23)(26,30)(28,36)(31,33)(34,40) involution — undirected(1,2,6,5)(3,8,4,7)(10,12)(11,13)(18,20)(19,21)(25,26)(27,31)(28,32)(29,30)(33,35)(34,38)(36,37)(39,40)(1,3,6,4)(2,7,5,8)(9,12,15,10)(11,17,13,16)(14,20,22,18)(19,24,21,23)(25,27)(26,31)(28,34)(29,35)(30,33)(32,38)(36,40)(37,39)(1,4,6,3)(2,8,5,7)(9,13,15,11)(10,17,12,16)(14,21,22,19)(18,24,20,23)(25,28,29,36)(26,32,30,37)(27,34,35,40)(31,38,33,39)(1,5,6,2)(3,8,4,7)(9,14,15,22)(10,18,12,20)(11,19,13,21)(16,23,17,24)(25,27)(26,31)(28,34)(29,35)(30,33)(32,38)(36,40)(37,39)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.